1. Technical Field
The exemplary embodiments disclosed herein relate to a photographing assisting apparatus that is used in combination with a photographing apparatus of any kind (for example, a camera of any kind such as a digital camera (including a camera-equipped portable appliance), film camera, or video camera, or an electronic image-sensing device of any kind such as a CCD imager, CMOS imager, or TFT imager) when a subject is photographed using the photographing apparatus, and relates also to a photographing method for photographing a subject using a photographing apparatus of any kind. More particularly, the exemplary embodiments relate to a photographing assisting apparatus and a photographing method that are useful in macro (close-up) photography. The exemplary embodiments relate further to a photographing system provided with a photographing apparatus and a photographing assisting apparatus as mentioned above.
2. Description of Related Art
Today, one common use of a camera is to photograph documents, business cards, and the like instead of copying them. When documents and the like are photographed using a camera, the distance between the subject and the camera is short, and so-called macro (close-up) photography therefore needs to be performed.
Such macro photography presents the following problems.
Typically used as an illumination light source in combination with a camera of any kind such as a digital camera is a built-in flash incorporated in the camera body or an external flash that is detachably attached to the camera body. When a flash is used as an auxiliary light source in macro photography, however, the subject is irradiated with flash light from a very close distance. It is therefore difficult to control the amount of light emitted and to shine light evenly over the entire area to be photographed. This tends to result in uneven exposure in the photographed image (hereinafter referred to as the first problem).
Moreover, macro photography is susceptible to the ambient illumination environment, often resulting in external illumination (such as the light from fluorescent lamps in the room or from the sun) or the shadow of the camera or of the photographer photographed together (hereinafter referred to as the second problem).
Moreover, macro photography not only is susceptible to camera shake, but also requires that the camera always be kept parallel to the subject, which is difficult (hereinafter referred to as the third problem).
Moreover, in macro photography, if the subject, for example a document, has a wrinkle, bend, warp, or fold, this part of the subject is illuminated irregularly. In an extreme case, this makes the corresponding part of the photographed image out of focus and thus unsharp (hereinafter referred to as the fourth problem).
Examples of solutions to the first problem are as follows. One conventionally proposed digital camera incorporates a lamp that emits softer light than a flash. In macro photography, illumination is achieved with the light emitted from this lamp so that light is shone evenly over the entire area to be photographed (see Japanese Patent Application Laid-Open No. H4-70274). Another conventionally proposed digital camera uses the liquid crystal display incorporated therein as a planar illumination light source so that light is shone evenly over the entire area to be photographed (see Japanese Patent Application Laid-Open No. 2000-75363).
Examples of solutions to the second and third problems are as follows. One conventionally proposed photographing method uses a close-up photographing apparatus that includes a hood for shielding external light and a holder for holding a camera in a desired position relative to the subject (see Japanese Patent Application Laid-Open No. H5-158149). Another conventionally proposed photographing method uses a box that shields external light and that has an illumination device housed inside it. The subject is placed inside the box, and is photographed using a camera placed at the top of the box (see Japanese Patent Application Laid-Open No. H9-133946).
The second and third problems mentioned above can be overcome by the photographing methods proposed in Japanese Patent Applications Laid-Open Nos. H5-158149 and H9-133946 mentioned above, namely by shielding external light and by holding a camera in position. However, the first problem mentioned above cannot be overcome satisfactorily with the digital cameras proposed in Japanese Patent Applications Laid-Open Nos. H4-70274 and 2000-75363 mentioned above.
As far as the applicant of the present invention has investigated, there are no publications that propose solutions to the fourth problem mentioned above.